They think he could have been targeted in Nigeria, where the Premier League champions played an exhibition game against Portsmouth.

The striker, 22, fell ill after the match two weeks ago and has yet to recover.

The Man Utd stars think there has been foul play because they all ate and drank the same things.

One United player said: "Wayne does eat and drink more than any of the other lads - and some say that might be why he was the only one who was ill."

And a club insider added: "There has been a lot of speculation as to what could have happened. It could have simply been a joke or something more sinister - such as part of a betting scam."